Automatic firearm



May 8, 923.

A. L. CHEVALLIYER AUTOMTIC FIREARM 5 Sheet's-Sheet 1 Filed rDec:4 12,1916 A. L. CHEVALLIER AUTOMATIC FIREARM May 8, 1923.

Filed Dec. l2. 1916 5 Sheets-Sheet 2 Il.. D

May 8, M923.

A. L. CHEVALLIER AUT OMAT I C FI REARM 1916 5 Sheets-Sheet 3 Filed Dec,l2

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A. L. CHEVALLIER AUT OMAT I C F I REARM 1916 5 Sheets-Sheet 5 Filed Dec.l2

Nw rwu Patented May 8, 1923. i

ARNOLD LOUIS CHEVALLIER, OF LONDON, ENGLAND.

AUTOMATIC FIREAIRM.

Application filed December 12, 19.16. Serial No. 136,531.

(GRANTED UNDER THE PROVISIONS F THE ACT 0F MARCH 3, 1921, 41 STAT. L.,1313.)

To all whom z't may concern.:

Be it known that I, ARNOLD LOUIS CHEVALLIER, a subject of the King ofGreat Britain, residing at 6 Knaresborough Place,

Cromwell Road, London, England, have invented new and usefulImprovements in Automatic Firearms (for which I have filed applicationsin Great Britain, Apr. 20, 1915, and Nov. 19` 1915), of which thefollowing is a specification. v

This invention relates to, improvements in automatic small arms of the'type which comprises' an inertia weight Within which are an unlockingspring and a firing spring l5 so arran ed that during the rearwardmovement o the barrel on recoil these two springs are compressed and thesubsequent expansion of the unlocking spring causes first a rotation ofthe bolt to unlock and then the rearward movement of the bolt, weightand bolt carrier, while the expansion of the firing spring is preventedby a sear engaging a bent on the firing pin, the forward movement of theweight and bolt being ei"-V fected by a closing spring or springs.

The object of the present invention is to render the automatic actionmore certain and to effect various other improvements in the weapon.

kThe invention is illustrated by the accompanying drawings, Figuresl and1a of which vare a. longitudinal section of a weapon Iliade inaccordance therewith; Figure 1b is a side view of the bolt; Figures 2and 3 '35 are tranverse sections on lines 2-2 and 3 3 respectively;Figure 4 shows a detail; Figures 5, 5a and 5" are a right hand elevationparts being in section and Figures '6, 6*l and 6J ay plan of a weaponsimilar in its action to that shown in Figures 1 and l but fitted with ajacket to prevent overheating. Figure 7 is a rear view of the weight andFigure "8 a transverse section through the muzzle and jacket. Figures 9and 9a are a left hand elevation of the shoe and weight; Figures .10 and10a are a plan of the shoe; Figure 11 is a front view of the weight andFigures 12 and 13 are sections on lines 12-12 and 13-13o Figures 9 and1() respectively. Figure 14 is a longitudinal :section and Figure 15 aplan of the racewa-y. Figure 16 is a longitudinal section of. theraceway showing the closing spring. Figure 17 is aside elevation ot theraceway and weight. Figure 18 is a section through the 55 boss on line18-18 of Figure 14. Figure 19 is a "section on the line 19-19 of Figure17. F igures 20, 21, 22 and 23 are sections on the lines en -ao. zi-Q1,ca 22, 23e-23,

of Figure 14, and Figure is a section on the line 24-24 of FigureFigures 25 and 26 are a left hand elevation. and a front view of thebolt carrier.

1 is the shoe, 2 the barrel, 3 the boss, 4 the raceway and 5 the weight.

The barrel is supported by two rings 'or tubes 6, 7, of which 6 is splitand isy carried by a block 8 which fits into the front of the shoe,being secured by a screw 9. Into the bloc-k 8 screws a rod 10 which car-7" ries at its rear end a strap 11 embracing and clamping the ring 6.The rings 6, 7, are kept at thfe correct distance apart by a sleeve l2surrounding the rod 10. The ring 7` which carries the foresight 13, issur- 75 -rounded and strengthened by a strap 14 into which the enlar edfront end of the rod 10 fits and whic is prolonged rear- Ward to formthe bayonet attachment.

The barrel is screwed with a leftwhanded 80 thread (so that the actionof the bullet on the riiing may tend to screw the barrel tighter) intothe boss 3 which is formed in one with the racewa-y 4. On the undersideof the latter is a feather 15 in the shape of an inverted T. This is ofsuch a length that in assembling it can enter the opening 16 in thelshoe through which the cartridges rise from the magazine 17. Thefeather engages grooves 18 cutl in the shoe. The boss also has upon itylateral ribs 19 which engage grooves 20 near the front of the shoe.

On the underside of the boss is alug 21 which enters through a slot 22(see Figure 95 10a) a cylindrical space 23 in the shoe Vand 26 which canbe moved transversely through grooves in the boss and shoe. This plungerhas in it a groove 27 so that when itis ink the position shown in Figure2, the boss can recoil, but when it is pushed transversely into itsother position in which it will be held by a spring 28 engaging a nick,movement between the recoiling and non-recoiling parts is prevented andthe weapon is no onger capable of automatic action.

In the space 23 and in front of the lug 21 is a cushioning spring 29adapted to prevent the recoiling part from hammering against thenon-recoiling part when itk is returned by the run-out spring. 30 is apiston mounted on a rod k31 and interposed between the lug and thespring 29.

32 is the bolt carried by the tubular bolt carrier 33 which surro-undsthe two springs 34, 35. The action of the weight, the bolt, the boltcarrier and the springs s very similar to that of the correspondingparts as described in British specification No. 16175 of 1912 exceptthatthe helical lugs and grooves are situated between the bolt and the boltcarrier. Normally the weight is locked to the non-recoiling part i. e.the shoe, by a lever 40 mount/ed on the right of the weapon on ahorizontal pivot 41 and having a lug 42 engaging a. shoulder 43 on theweight.

On recoil a stud 44 on the boss comes against an incline 45 onl thelever and turns it down withdrawing the lug 42 from behind the shoulder43 so that the weight is freed. 46 is a spring which presses the leverupward into its operative position and the movement of the lever islimited by a stud 47. In order that it may be possible readily torelease the weight when desired, the lever is prolonged upwards andcarries a thumbpiece 48. On firing theretore the weight remainsstatonaryand the barrel, bolt carrier and bolt recoil relatively tothe weight,compressing the springs 34 and 35; the spring 35 is. as will bedescr'bed later, prevented from expanding, but when 44 comes againstincline 45, the weight is freed from the shoe and the spring 34 expandsdriving the weight rearward frelatively to the bolt carrier. This is theonly function of the spring 34. The weight and carrier then recoiltogether and move rearward away from the barrel and boss which are nowchecked by the run-out sprng: the the helical-lugs 321 (see Figure 1b)and grooves now rotate the bolt for one sixteenth part of a revolutionto unlock and 4for' carrier 33 and the bolt does not start recoilingaway from the bossk until the carrier has moved away from it about halfan inch. It then moves rearward with the carrier and is prevented fromturning by the engagement of a tooth 36 formed upon it with a groove 37in the ra'ceway. At the end of the forward movement of the bolt thistoothleaves the end of the groove and the bolt is turned to lock by themomentum of the weight and carrier.

The movement of the bolt carrier relative to the weght is limited by astud 3S screwed'into the weight and entering a slot in the bolt carrier.y It will be seen that the entire movement of the barrel 4and racewayrelatively to the shoe iscgreater than the movement of the barrel. boltcarrier and bolt relative to the weight before the unlocking but is lessthank twice that movement. Rotation of the carrier within the weight isprevented by a guide rod 39 which projects rearward from the front ofthe carrier and enters a longitudinal hole bored in the weight.

The closing spring 49 is contained in a tubular cas'ng 50 as shown inFigures 15 and 16. In front of the spring is a plug 51 having on it atooth 52 which extends out through a slot 53 in the casing 50 andengages an arm 54 on the bolt carrien The closing spring is preferablymade in two kparts with aL double thimble 55 between them.

Or `I may connect the carrier to `the closing spring as shown in Figures17, 19, 25 and 26 by a lever 56 pivoted on a long`tudinal pivot 57 in,the carrier and having an arm 58 passing through a slot in the racewayand engaging an annular groove 59 in a plug 60 at the front of thespring. The lever is normally kept in engagement by a spring'61 againstwhich it can be turned by hand when it is desired to disconnect thecarrier from the spring. The operation is as follows s-On discharge theweight being locked to the shoe by parts 42 and 43 the barrel andraceway recoil against spring 24 until stopped by pin 25. During thispart of the recoil spring 34 is compressed by the bolt carrier andspring 35 is compressed by the firing pin; stud 44 then comes againstpart 45 of lever 40 which frees weight 5. Spring 34 is therefore free toexpand, driving weight 5 and carrier 33 rearwardly slightly relative tobolt and barrel. The bolt is therefore turned owing to the engagement ofits helical lugs 321 with the corresponding grooves in the interior istherefore unlocked from the boss 3.v The weight, its springs, the boltcarrier and bolt are therefore free to move rearward, which they do,compressing spring 49. As this spring expands again it moves the boltcarrier, bolt and weight forward again and the carrier thrusts llUrealices the bolt inte the barrel and loclrs it, und rhe piece is readylo lire.

ln Figure 6 is shown e supplementary hurler 62 and run-out spring 63lying in e hole in ehe raceway and bearing againsiJ a stop pillar 6lwhich carries the backsight.

'lhe rearward movement of the weight is normally limited by a peil ofshops y65 carried by e spring blade 66. These stops lie in ihe path ofshoulders 67 on the side walls of the weight. Should it be desired *towithdrew the weightI beyond its normal rearmost position, +che blade canbe benl; down by pressing on ihe stops with the ngers.

' 'lhe ,motion of the weightl in front of its normal posifon isprevented by a sind 68 on the shoe (see Figures 9 and l0.)

ylhe operating lever 69 surrounds the rear parl; of the weight and hasupon il toes 70 adapted io engage slots 7l at the rear of ihe raceway loretain the anti-recoiling part, when lhe lever is turned into thecorrect position, au, the rear of the hand iravel and to engage slots 72 in the middle of the racewey when ihe lever is iurned right over ihedotted position of Figure e. l ln thls posirion the weapon is safe as*che cam suriece of che lever 69 then lies in lhe path of the tail 73 ci1the firing pin 74 and prevents ii moving `forward lo lire.

The pinl 74 passes through the boli and JLhrough 4he rear parl of theweight and iis rear end is flat et the sides (see Figure 3) io preventil from turning on its axis'. A bent is formed in it by removing aportion or it and; ai: this bent it is surrounded by e ring 75 presseddownwards by a spring 76 in ihe lop oi ithe weight. When the pin 7lmoves lo die rear ai: the commencement oi recoil, that is, before bheweigh"J parishes in ihe recoil, 'ehe ring 75 drops vinto the posiiion inwhich it is shown in Figures l and 3 and prevents the iring spring fromexpanding, thai is, keeps the weapon cocked.

77 is the trigger pivored on -a rensverse axis '78 and having aforwardly projecting erin 7S, Jehe iront or which carries a pivoied nose80 pressed against la stop 8l by a spring 82. This nose normally restsagainst :i shoulder 83 ai, the rear of a lever 8e pivoted on a ransversestud 85; ehe front of this lever lies beiween the jaws of a piece 86nomally held down by a spring 87. Beiween ihe piece 86 and the ring 75is plunger 88. llhen the trigger is pulled the nose 80 rocks the lever84 which raises the plunger 88 and this lifts the ring 75, thus allowingJche pin 7l lo ily forward and lire. The nose 80 slips oil 'the end ofthe lever 8l which is restored to the position shown by the spring 87.When the trigger is released' it is refrurned to the position shown bythe irigger spring 89 and the nose turns on its pivot ageinsi its spring82 so that it can rise into the position of engagement.

In order to prevenl the magazine spring 90 from raising the nexh`cartridge too quiclrl e. rib el is provided on. the under side o thebolt carrier 33 which holds down the earridge while the bolt carrier ismov? ing rearward. en this movement is complete, the cartridge risesslighily und is then held down by a, plate or frame 92 (see Fig. ures 22and 24) working in a slot in the righi: or the raceway. This fre is heldby e spring 93 in the position shown so thet il; prevenls `the cartridgerising until the latter is pushed forwerd and upward-by the bolt withforce sudicienil to press the piel/e inward against the spring and thecartridge then entiers rhe chamber.

ln some cases ll provide the barrel willi n cooling jacket 94 es shownin Figures '5, d and 8. ln this case the barrel is not supported by eherings 6, 7 and siraps ll end 14, but the jacket is carried by a ring 95which can turn on e horizonial pivot 96 ai the iront or' the shoe. rl`hemuzzle is secured v to the front of the jacket by a oep 97 havinginwardly projecting ribs 98 which pass through slots in the irona oi thejechet and embrace the muzzle which is :made octegonfal.7 99 is a shieldwhich springs over ehe rear `of the jacket and encloses the hess andfront of the sides oi the weigh-.iJ so ther, there is no danger of thethumb or linger being caught between the moving paris.

l. ln en automatic lire arm, the combinetion of a shoe, a magazine andirigger mech anism both fast with the shoe, a barrel, e raceway securedto the barrel, the barrel and raceway being capable of recoiling upon.the shoe, a weight capable of sliding on the raceway, means fornormally locking the weight to ihe shoe and a boli carrier and. boltwithin 'the weighs.

2. ln an automatic lire erin, fthe combinerion oi? a shoe, a magazineand irigger mech anism both fast with the shoe, a barrel, e raceweysecured to the barrel, the barrel and ee l iin

raceway being capable of recoiling upon the shoe, e. weighs capable ofsliding on elle raceway, means for normally locking the weight lo theshoe, end a bolt carrier end boltwithin the weight. he distance hroughwhich the barrel and rnceway can move relatively to the shoe bearing tohe disence through which the barrehboll carrier and bolt can inoverelatively lo ihe weighh a ratio that does not exceed 2:1 end is noi;less than unii'v.

ln an euomatic dre arm, combination of a shoe. n magazine and riggermechanism hoih 'fast wih he shoe, a barrel, a

raceway secured lo the harrel, lthe barrel and racewny being capable ofiecoiling upon the shoe. e weight capable ci sliding on he raceway.ineens for normally locking `the weight .fthe shoe, s bolt carrier andholt tion of a shoe, a magazine and trigger mechanism both fast with theshoe, a raceway free to recoil upon the shoe, a barrel secured to theraceway, a weight capable of rearward movement upon the raceway, meansfor norlU mally locking the weight to the shoe, means whereby therecoil. of thev barrel and raceway relative to the shoe releases theweight from the shoe, a bolt, means for locking the bolt to the barrel,a bolt carrier disposed l5 within the weight and having within ithelical grooves engaging helical lugs on the bolt and a spring betweenthe bolt carrier and the weight.

' 5. In an automatic fire arm, the combination of a shoe, a magazine andtrigger mechanism both tast with the shoe, a raceway free to recoil uponthe shoe, a barrel secured to the raceway, a weight capable of rearwardmovement upon the raceway, means for normally locking the weight to theshoe, means whereby the recoil of the barrel and raceway relative to theshoe releases the ,weight from the shoe, a bolt, means for locking thebolt to the barrel, a bolt carrier disposed within 3" the weight andhaving within it helical grooves engaging helical lugs on the bolt, aspring between the bolt carrier and the weight, and a firing pin withinthe bolt and a' firing spring between the firing pin and.,l the weight.

6. In an automatic fire arm, the combination of a shoe, a magazine andtrigger mechanism both fast with the shoe, a barrel, a raceway securedto the barrel, the barrel and 4o raceway being capable of recoiling uponthe shoe, a weight capable of sliding on the raceway, means for normallylocking the weight to the shoe, a bolt carrier and bolt within theweight, a lug on the raceway projecting v4.3 into a space formed in theshoe and a runout spring contained in the space and bearing against thelug.

l. In an automatic fire arm, the combination of a shoe, a magazine andtrigger mechanism both fast with the shoe, a barrel, a

raceway secured to the barrel, the barrel and raceway being capable ofrecoiling upon the shoe, a weight capable of sliding on' the raceway,means for normally locking the weight to the shoe, a bolt carrier andbolt within the weight and means for preventing movement of the racewayand barrel relative 'to the shoe.

8. In an automatic firearm, the combinaun tion of a shoe, a magazine andtrigger mechanism both fast with the shoe, a barrel, a raceway securedto the barrel, the barrel and raceway being capable of recoiling uponthe shoe, a weight capable of sliding on the race- 55 way, means fornormally locking the weight magos@ to the shoe, a bolt carrier and boltwithin the weight, a lug on the raceway projecting into a space l:formedin the shoe, a run-out spring contained in the space and bearing againstthe lug and means for preventing movement o the raceway and barrelrelative to the s oe.

9. In an automatic re arm, the combination of a shoe, a magazine andtrigger meehanism both fast with the shoe, a raceway, a barrel securedto the raceway, a feather on the underside of the raceway adapted to bemserted through the magazine opening in the shoe and to enter a roovetherein, a weight capable of rear warg movement along the raceway andmeans for normally locking the weight to the shoe.

10. In an automatic fire arm, the combination of a shoe, a magazine andtrigger mechanism both fast with the shoe, a rin supported at the frontof the shoe, a ro proj ecting forward from the ring, a second ringcarried by the front end of the rod, a raceway adapted to slide upon theshoe, a barrel secured to the raceway and adapted to be supported by andto slide in the two rings, a weight capable of rearward movement on theraceway and means for normally locking the weight to the shoe.

11. In an automatic fire arm, the combination of a shoe, a magazine andtrigger mechanism both fast with the shoe, a ring suported at the frontof the shoe, a rod projecting forward from the ring, a second ringcarried by the ro'nt end ofthe rod, a raceway adapted to slide ipon theshoe, a barrel secured to the raceway and adapted to be supported by andto slide in the two rings, a ug protruding from the raceway into acylindrical space formed in the shoe, a runout spring located in saidspace and bearing against the lug, a weight capable of rearward movementon the raceway and means flclxr normally locking the vwreight to be soe.

12. In an automatic fire arm, the combination of a shoe, a magazine andtrigger mechanism both fast wlth the shoe, a raceway free to recoil uponthe shoe,`a barrel secured to the raceway, a weight capable of rearwardmovement along the raceway, a horizontal transverse pivot Fcarried b theshoe, a lever mounted on the pivotan engaging the weight and' meansadapted on recoil to turn the lever out of engagement with the Weight.13. In an automatic fire arm, the combination of a shoe, a magazine andtrigger mechanism both fastv with the shoe, a raceway free to recoilupon the shoe, a barrel secured to the raceway, a weight capable ofrearward movement along the raceway, means for normally lockingtheweight to the shoe and a shield adapted to cover the rear of the barreland the front of the weight.

ini

14. In an automatic fire arm, the combinaa firing pin and spring carriedby the weight, tion of a shoe, a magazine and trigger mecha sear ringadapted to engage a groove in the anism both fast with the shoe, araceway pin and a plunger adapted to be actuated by 10- free to recoilupon the shoe, a barrel secured the trigger mechanism and to lift thering 5 to the raceway, a Weight capable of rearout of the groove.

ward movement along the raceway, means for normally locking the weightto the shoe,t ARNOLD LOUIS CHEVALLIER.

